Emerson 644 User manual

Brand: Emerson

Model: 644

Category: Measuring, testing & control

Type: User manual

www.rosemount.com

Reference Manual

00809-0400-4728, Rev AA

June 2011

Rosemount 644 Temperature Transmitter

with FOUNDATION

™

fieldbus

Reference Manual

00809-0400-4728, Rev AA

June 2011

Rosemount 644

TOC-1

SECTION 1

Introduction

Safety Messages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Commissioning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Electrical. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Environmental. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Return of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Product Recycling/Disposal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

SECTION 2

Installation

Safety Messages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Typical European Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Typical North American Installation . . . . . . . . . . . . . . . . . . . . . . . . 2-5

LCD Display Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Wiring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

Sensor Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

Ground the Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

SECTION 3

Configuration

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Safety Messages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

General Block Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Device Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Node Address. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Link Active Scheduler. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Block Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Capabilities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Foundation fieldbus function blocks. . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Resource Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Sensor Transducer Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

Analog Input (AI) Function Block . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

LCD Transducer Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

Operation and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15

Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15

Troubleshooting Guides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16

Sensor Transducer Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18

Analog Input (AI) Function Block . . . . . . . . . . . . . . . . . . . . . . . . . 3-21

Resource Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23

LCD Transducer block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24

Table of Contents

Reference Manual

00809-0400-4728, Rev AA

June 2011

TOC-2

Rosemount 644

APPENDIX A

Specifications and

Reference Data

Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1

Functional. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1

Physical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2

Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-3

Foundation Fieldbus Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . .A-4

Dimensional Drawings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-9

Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-12

Tagging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-14

Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-14

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-15

APPENDIX B

Product

Certifications

Approved Manufacturing Locations . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1

European Union Directive Information. . . . . . . . . . . . . . . . . . . . . . . . .B-1

Hazardous Locations Certificates . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-2

Rosemount 644 with Foundation fieldbus. . . . . . . . . . . . . . . . . . . .B-2

North American Certifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-2

European Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-3

IECEx Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-4

Japanese Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-6

Combination Approvals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-6

Russian GOST Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-6

Kazakhstan GOST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-6

Ukraine GOST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-6

Installation Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-7

APPENDIX C

Foundation

fieldbus Block

Information

Basic Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-1

Resource Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-1

Parameters and Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-2

Sensor Transducer Block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-5

Parameters and Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-5

Analog Input (AI) Function Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-8

AI Parameter Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-9

LCD Transducer Block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-11

PID Block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-12

Reference Manual

00809-0400-4728, Rev AA

June 2011

Rosemount 644

www.rosemount.com

Rosemount 644

Temperature Transmitters

Rosemount 644 Hardware Revision

OUNDATION

™

Fieldbus Device Revision

Device Descriptor Revision

NOTICE

Read this manual before working with the product. For personal and system safety, and for

optimum product performance, make sure to thoroughly understand the contents before

installing, using, or maintaining this product.

The United States has two toll-free assistance numbers and one international number.

Customer Central

1-800-999-9307 (7:00 a.m. to 7:00 p.m. CST)

National Response Center

1-800-654-7768 (24 hours a day)

Equipment service needs

International

1-(952)-906-8888

The products described in this document are NOT designed for nuclear-qualified

applications.

Using non-nuclear qualified products in applications that require nuclear-qualified hardware

or products may cause inaccurate readings.

For information on Rosemount nuclear-qualified products, contact a Emerson Process

Management Sales Representative.

Reference Manual

00809-0400-4728, Rev AA

June 2011

Rosemount 644

www.rosemount.com

Section 1 Introduction

Safety Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 1-1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 1-2

Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 1-3

Return of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 1-4

SAFETY MESSAGES Instructions and procedures in this section may require special precautions to

ensure the safety of the personnel performing the operations. Information that

potentially raises safety issues is indicated by a warning symbol ( ). Please

refer to the following safety messages before performing an operation

preceded by this symbol.

Warnings

Failure to follow these installation guidelines could result in death or

serious injury.

• Make sure only qualified personnel perform the installation.

Explosions could result in death or serious injury.

• Do not remove the connection head cover in explosive atmospheres when the

circuit is live.

• Before connecting F

OUNDATION fieldbus in an explosive atmosphere, make sure

the instruments in the loop are installed in accordance with intrinsically safe or

non-intrinsic field wiring practices.

• Verify that the operating atmosphere of the transmitter is consistent with the

appropriate hazardous locations certifications.

• All connection head covers must be fully engaged to meet

explosion-proof requirements.

Process leaks could result in death or serious injury.

• Do not remove the thermowell while in operation.

• Install and tighten thermowells and sensors before applying pressure.

Electrical shock could cause death or serious injury.

• Use extreme caution when making contact with the leads and terminals.

Reference Manual

00809-0400-4728, Rev AA

June 2011

Rosemount 644

1-2

OVERVIEW

Manual This manual is designed to assist in the installation, operation, and

maintenance of Rosemount 644 head mount and 644 rail mount.

Section 1: Introduction

• Transmitter and Manual Overview

• Considerations

• Return of Material

Section 2: Installation

• Mounting

• Installation

• Wiring

• Power Supply

• Commissioning

Section 3: Configuration

• Calibration

• Hardware Maintenance

• Diagnostic Messaging

Appendix A: Specifications and Reference Data

• Specifications

• Dimensional Drawings

• Ordering Information

• Biotechnology, Pharmaceutical Industries, and Sanitary Applications

Appendix B: Product Certifications

• Product Certifications

• Installation Drawings

Appendix C: Foundation fieldbus Block Information

• Information regarding the Function Blocks

Transmitter Features of the Rosemount 644 include:

• Accepts inputs from a wide variety of sensors

• Configuration using F

OUNDATION fieldbus

• Electronics that are completely encapsulated in epoxy and enclosed in

a metal housing, making the transmitter extremely durable and

ensuring long-term reliability

• A compact size and two housing options allowing mounting flexibility for

the control room or the field

Reference Manual

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June 2011

1-3

Rosemount 644

Refer to the following literature for a full range of compatible connection

heads, sensors, and thermowells provided by Emerson Process

Management.

• Temperature Sensors and Assemblies Product Data Sheet, Volume 1

(document number 00813-0100-2654)

• Temperature Sensors and Assemblies Product Data Sheet, Volume 2

(document number 00813-0200-2654)

CONSIDERATIONS

General Electrical temperature sensors such as RTDs and thermocouples produce

low-level signals proportional to their sensed temperature. The 644 converts

the low-level sensor signal to a standard 4–20 mA dc, or digital F

OUNDATION

fieldbus signal that is relatively insensitive to lead length and electrical noise.

This signal is then transmitted to the control room via two wires.

Commissioning The transmitter can be commissioned before or after installation. It may be

useful to commission it on the bench, before installation, to ensure proper

operation and to become familiar with its functionality. Make sure the

instruments in the loop are installed in accordance with intrinsically safe,

FISCO, or non-incendive field wiring practices.

Mechanical Location

When choosing an installation location and position, take into account the

need for access to the transmitter.

Special Mounting

Special mounting hardware is available for mounting a 644 head mount

transmitter to a DIN rail or assembling a new 644 head mount to an existing

threaded sensor connection head (former option code L1).

Electrical Proper electrical installation is necessary to prevent errors due to sensor lead

resistance and electrical noise. For best results, shielded cable should be

used in electrically noisy environments.

Make wiring connections through the cable entry in the side of the connection

head. Be sure to provide adequate clearance for cover removal.

Environmental The transmitter electronics module is permanently sealed within the housing,

resisting moisture and corrosive damage. Verify that the operating

atmosphere of the transmitter is consistent with the appropriate hazardous

locations certifications.

Temperature Effects

The transmitter will operate within specifications for ambient temperatures

between –40 and 185 °F (–40 and 85 °C). Heat from the process is

transferred from the thermowell to the transmitter housing. If the expected

process temperature is near or beyond specification limits, consider the use of

additional thermowell lagging, and extension nipple, or a remote mounting

configuration to isolate the transmitter from the process.

Figure 1-1 provides an example of the relationship between transmitter

housing temperature rise and extension length.

Reference Manual

00809-0400-4728, Rev AA

June 2011

Rosemount 644

1-4

Figure 1-1. 644 head mount

Transmitter Connection Head

Temperature Rise vs. Extension

Length

Example

The transmitter specification limit is 85 °C. If the ambient temperature is 55 °C

and the process temperature to be measured is 800 °C, the maximum

permissible connection head temperature rise is the transmitter specification

limit minus the ambient temperature (moves 85 to 55 °C), or 30 °C.

In this case, an extension of 100 mm meets this requirement, but 125 mm

provides a margin of 8 °C, thereby reducing any temperature effects in the

transmitter.

RETURN OF MATERIALS To expedite the return process in North America, call the Emerson Process

Management National Response Center toll-free at 800-654-7768. This

center, available 24 hours a day, will assist you with any needed information

or materials.

The center will ask for the following information:

• Product model

• Serial numbers

• The last process material to which the product was exposed

The center will provide

• A Return Material Authorization (RMA) number

• Instructions and procedures that are necessary to return goods that

were exposed to hazardous substances

For other locations, please contact a Emerson Process Management sales

representative.

NOTE

If a hazardous substance is identified, a Material Safety Data Sheet (MSDS),

required by law to be available to people exposed to specific hazardous

substances, must be included with the returned materials.

PRODUCT

RECYCLING/DISPOSAL

Recycling of equipment and packaging should be taken into consideration

and disposed of in accordance with local and national legislation/regulations.

Housing Temperature Rise, Above

Ambient °C (°F)

3 4 5 6 7 8 9

60 (108)

50 (90)

40 (72)

30 (54)

20 (36)

10 (18)

3.6

Extension Length (in.)

815 °C (1500 °F) Oven Temperature

540 °C (1000 °F)

Oven Temperature

250 °C (482 °F) Oven Temperature

Reference Manual

00809-0400-4728, Rev AA

June 2011

Rosemount 644

www.rosemount.com

Section 2 Installation

Safety Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 2-1

Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 2-3

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 2-4

Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 2-7

Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 2-11

SAFETY MESSAGES Instructions and procedures in this section may require special precautions to

ensure the safety of the personnel performing the operations. Information that

potentially raises safety issues is indicated by a warning symbol ( ). Please

refer to the following safety messages before performing an operation

preceded by this symbol.

Warnings

Failure to follow these installation guidelines could result in death or

serious injury.

• Make sure only qualified personnel perform the installation.

Explosions could result in death or serious injury.

• Do not remove the connection head cover in explosive atmospheres when the

circuit is live.

• Before connecting a Field Communicator in an explosive atmosphere, make sure

the instruments in the loop are installed in accordance with intrinsically safe or

non-incendive field wiring practices.

• Verify that the operating atmosphere of the transmitter is consistent with the

appropriate hazardous locations certifications.

• All connection head covers must be fully engaged to meet

explosion-proof requirements.

Process leaks could result in death or serious injury.

• Do not remove the thermowell while in operation.

• Install and tighten thermowells and sensors before applying pressure.

Electrical shock could cause death or serious injury.

• Use extreme caution when making contact with the leads and terminals.

Reference Manual

00809-0400-4728, Rev AA

June 2011

Rosemount 644

2-2

Figure 2-1. Installation Flowchart

START

HERE

Bench

Calibration?

BASIC SETUP

Set Sensor Type

Set Number of Wires

Set Units

Set Range Values

Set Damping

VERIFY

Simulate Sensor Input

Within

Specifications?

Refer to Section 3: Configuration

FIELD INSTALL

Set Failure Mode

Switch

Mount Transmitter

Wire Transmitter

Power Transmitter

FINISHED

Does not apply to the 644

with F

OUNDATION fieldbus

Reference Manual

00809-0400-4728, Rev AA

June 2011

2-3

Rosemount 644

MOUNTING Mount the transmitter at a high point in the conduit run to prevent moisture

from draining into the transmitter housing.

The 644 head mount installs:

• In a connection head or universal head mounted directly on a sensor

assembly

• Apart from a sensor assembly using a universal head

• To a DIN rail using an optional mounting clip.

The 644 rail mount attaches directly to a wall or to a DIN rail.

Mounting a 644H to a DIN Rail

To attach a head mount transmitter to a DIN rail, assemble the appropriate rail

mounting kit (part number 00644-5301-0010) to the transmitter as shown in

Figure 2-2.

Figure 2-2. Assembling Rail Clip

Hardware to a 644H

Retrofitting a 644H for Use in an Existing Threaded Sensor Connection

Head

To mount a 644H in an existing threaded sensor connection head (former

option code L1), order the 644H retrofit kit (part number 00644-5321-0010).

The retrofit kit includes a new mounting bracket and all associated hardware

necessary to facilitate the installation of the 644H in the existing head. See

Figure 2-3.

Figure 2-3. Assembling 644H for

Use in an Existing L1

Connection Head

G-Rail (asymmetric) Top Hat Rail (symmetric)

Note: Kit includes Mounting Hardware and both types of Rail Kits.

Transmitter

Mounting

Hardware

Rail Clip

Transmitter

Mounting

Hardware

Rail Clip

Kit includes

replacement bracket

and screws.

Existing Threaded Sensor Connection Head

(Former option code L1)

Reference Manual

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June 2011

Rosemount 644

2-4

INSTALLATION

Typical European

Installation

Head Mount Transmitter with DIN Plate Style Sensor

1. Attach the thermowell to the pipe or process container wall. Install

and tighten the thermowell before applying process pressure.

2. Assemble the transmitter to the sensor. Push the transmitter

mounting screws through the sensor mounting plate and insert the

snap rings (optional) into the transmitter mounting screw groove.

3. Wire the sensor to the transmitter (see Figure 2-7 on page 2-8).

4. Insert the transmitter-sensor assembly into the connection head.

Thread the transmitter mounting screw into the connection head

mounting holes. Assemble the extension to the connection head.

Insert the assembly into the thermowell.

5. Attach a cable gland into the shielded cable.

6. Insert the shielded cable leads into the connection head through the

cable entry. Connect and tighten the cable gland.

7. Connect the shielded power cable leads to the transmitter power

terminals. Avoid contact with sensor leads and sensor connections.

8. Install and tighten the connection head cover. Enclosure covers must

be fully engaged to meet explosion-proof requirements.

A = 644H Transmitter D = Transmitter Mounting Screws

B = Connection Head E = Integral Mount Sensor with Flying Leads

C = Thermowell F = Extension

Reference Manual

00809-0400-4728, Rev AA

June 2011

2-5

Rosemount 644

Typical North American

Installation

Head Mount Transmitter with Threaded Sensor

1. Attach the thermowell to the pipe or process container wall. Install

and tighten thermowells before applying process pressure.

2. Attach necessary extension nipples and adapters to the thermowell.

Seal the nipple and adapter threads with silicone tape.

3. Screw the sensor into the thermowell. Install drain seals if required for

severe environments or to satisfy code requirements.

4. Pull the sensor wiring leads through the universal head and

transmitter. Mount the transmitter in the universal head by threading

the transmitter mounting screws into the universal head mounting

holes.

5. Mount the transmitter-sensor assembly into the thermowell. Seal

adapter threads with silicone tape.

6. Install conduit for field wiring to the conduit entry of the universal

head. Seal conduit threads with silicone tape.

7. Pull the field wiring leads through the conduit into the universal head.

Attach the sensor and power leads to the transmitter. Avoid contact

with other terminals.

8. Install and tighten the universal head cover. Enclosure covers must

be fully engaged to meet explosion-proof requirements.

A = Threaded Thermowell D = Universal Head

B = Threaded Style Sensor E = Conduit Entry

C = Standard Extension

Reference Manual

00809-0400-4728, Rev AA

June 2011

Rosemount 644

2-6

LCD Display Installation The LCD display provides local indication of the transmitter output and

abbreviated diagnostic messages governing transmitter operation.

Transmitters ordered with the LCD display are shipped with the meter

installed. After-market installation of the meter can be performed if the

transmitter has a meter connector (transmitter revision 5.5.2 or later).

After-market installation requires the meter kit (part number

00644-4430-0001), which includes:

• LCD display assembly (includes LCD display, meter spacer,

and 2 screws)

• Meter cover with O-ring in place

Figure 2-4. Installing the LCD

Display

Use the following procedure to install the meter.

1. If the transmitter is installed in a loop, secure the loop and disconnect

the power. If the transmitter is installed in an enclosure, remove the

cover from the enclosure.

2. Decide meter orientation (the meter can be rotated in 90°

increments). To change meter orientation, remove the screws located

above and below the display screen. Lift the meter off the meter

spacer. Remove the 8-pin plug and re-insert it in the location that will

result in the desired viewing orientation.

3. Reattach the meter to the meter spacer using the screws. If the meter

was rotated 90° from its original position, it will be necessary to

remove the screws from their original holes and re-insert them in the

adjacent screw’s holes.

4. Line up the 10-pin connector with the 10-pin socket and push the

meter into the transmitter until it snaps into place.

5. Attach the meter cover; tighten at least one-third turn after the O-ring

contacts the transmitter housing. The cover must be fully engaged to

meet explosion-proof requirements.

6. Use a Field Communicator, AMS software, or a F

OUNDATION fieldbus

Communication tool to configure the meter to the desired display.

NOTE

Observe the following LCD display temperature limits:

Operating: –4 to 185 °F (–20 to 85 °C)

Storage: –50 to 185 °F (–45 to 85 °C)

644H

Captive Mounting Screws and Springs

Meter Spacer

LCD Display

10 pin Connector

Reference Manual

00809-0400-4728, Rev AA

June 2011

2-7

Rosemount 644

WIRING All power to the transmitter is supplied over the signal wiring. Use ordinary

copper wire of sufficient size to ensure that the voltage across the transmitter

power terminals does not drop below 9 Vdc.

If the sensor is installed in a high-voltage environment and a fault condition or

installation error occurs, the sensor leads and transmitter terminals could

carry lethal voltages. Use extreme caution when making contact with the

leads and terminals.

NOTE

Do not apply high voltage (e.g., ac line voltage) to the transmitter terminals.

Abnormally high voltage can damage the unit. (Sensor and transmitter power

terminals are rated to 42.4 Vdc. A constant 42.4 volts across the sensor

terminals may damage the unit.)

The transmitters will accept inputs from a variety of RTD and thermocouple

types. Refer to Figure 2-5 on page 2-7 when making sensor connections.

Refer to Figure 2-6 on page 2-8 for F

OUNDATION fieldbus installations.

Use the following steps to wire the power and sensor to the transmitter:

1. Remove the terminal block cover (if applicable).

2. Connect the positive power lead to the “+” terminal. Connect the

negative power lead to the “–” terminal (see Figure 2-7).

3. Tighten the terminal screws. When tightening the sensor and power

wires, the max torque is 6-in.-lbs (0.7 N-m).

4. Reattach and tighten the cover (if applicable).

5. Apply power (see “Power Supply”).

Figure 2-5. Transmitter Power,

Communication, and Sensor

Terminals

644H

1 2 3 4

Sensor

Terminals

Communication

Terminals

Power Terminals

Reference Manual

00809-0400-4728, Rev AA

June 2011

Rosemount 644

2-8

Figure 2-6. Connecting a

OUNDATION fieldbus Host

System to a Transmitter Loop

Sensor Connections The 644 is compatible with a number of RTD and thermocouple sensor types.

Figure 2-7 shows the correct input connections to the sensor terminals on the

transmitter. To ensure a proper sensor connection, anchor the sensor lead

wires into the appropriate compression terminals and tighten the screws.

Figure 2-7. Sensor Wiring

Diagrams

Thermocouple or Millivolt Inputs

The thermocouple can be connected directly to the transmitter. Use

appropriate thermocouple extension wire if mounting the transmitter remotely

from the sensor. Make millivolt inputs connections with copper wire. Use

shielding for long runs of wire.

Power

Supply

6234 ft (1900 m) max

(depending upon cable characteristics)

Integrated Power

Conditioner and Filter

Terminators

(Spur)

(Trunk)

(The power supply,

filter, first

terminator, and

configuration

tool are typically

located in the

control room.)

Devices 1

through 16

OUNDATION

fieldbus

Configuration

Tool

Power/

Signal

Wiring

644 Sensor Connections Diagram

* Emerson Process Management provides 4-wire sensors for all single element RTDs. Use these

RTDs in 3-wire configurations by leaving the unneeded leads disconnected and insulated with electrical

tape.

2-wire

RTD and 

3-wire RTD

and 

4-wire RTD

and 

T/C

and mV

1234

Reference Manual

00809-0400-4728, Rev AA

June 2011

2-9

Rosemount 644

RTD or Ohm Inputs

The transmitters will accept a variety of RTD configurations, including 2-wire,

3-wire, or 4-wire. If the transmitter is mounted remotely from a 3-wire or 4-wire

RTD, it will operate within specifications, without recalibration, for lead wire

resistances of up to 60 ohms per lead (equivalent to 6,000 feet of 20 AWG

wire). In this case, the leads between the RTD and transmitter should be

shielded. If using only two leads, both RTD leads are in series with the sensor

element, so significant errors can occur if the lead lengths exceed three feet

of 20 AWG wire (approximately 0.05 °C/ft). For longer runs, attach a third or

fourth lead as described above.

Sensor Lead Wire Resistance Effect– RTD Input

When using a 4-wire RTD, the effect of lead resistance is eliminated and

has no impact on accuracy. However, a 3-wire sensor will not fully cancel

lead resistance error because it cannot compensate for imbalances in

resistance between the lead wires. Using the same type of wire on all

three lead wires will make a 3-wire RTD installation as accurate as

possible. A 2-wire sensor will produce the largest error because it directly

adds the lead wire resistance to the sensor resistance. For 2- and 3-wire

RTDs, an additional lead wire resistance error is induced with ambient

temperature variations. The table and the examples shown below help

quantify these errors.

Table 2-1. Examples of

Approximate Basic Error

Examples of Approximate Lead Wire Resistance Effect Calculations

Given:

• Pt100 4-wire RTD: No lead wire resistance effect.

• Pt100 3-wire RTD:

Sensor Input Approximate Basic Error

4-wire RTD None (independent of lead wire resistance)

3-wire RTD ± 1.0  in reading per ohm of unbalanced lead wire resistance

(Unbalanced lead wire resistance = maximum imbalance between

any two leads.)

2-wire RTD 1.0  in reading per ohm of lead wire resistance

Total cable length: 150 m

Imbalance of the lead wires at 20 °C: 1.5 

Resistance/length (18 AWG Cu): 0.025 /m °C

Temperature coefficient of Cu (

): 0.039 / °C

Temperature coefficient of Pt(

): 0.00385 / °C

Change in Ambient Temperature (T

amb

): 25 °C

RTD Resistance at 0 °C (R

): 100  (for Pt 100 RTD)

Basic Error

Imbalance of Lead Wires





------------------------------------------------------------------=

Error due to amb. temp. variation



T

amb

 Imbalance of Lead Wires



R



-------------------------------------------------------------------------------------------------------------------------

Reference Manual

00809-0400-4728, Rev AA

June 2011

Rosemount 644

2-10

Lead wire imbalance seen by the transmitter = 0.5 

• Pt100 2-wire RTD:

Lead wire resistance seen by the transmitter = 150 m × 2 wires ×

0.025

/m = 7.5 

Basic error

0.5 

0.00385  /  C100 

--------------------------------------------------------------------------------- - 1.3 C==

Error due to amb. temp. var. of 25 °C

0.0039  /  C25 C 0.5 

0.00385  /  C100

-------------------------------------------------------------------------------------------------------

0.1266C==

Basic Error

Lead Wire Resistance





----------------------------------------------------------

Error due to amb. temp. variation



T

amb

 Lead Wire Resistance



R



-----------------------------------------------------------------------------------------------------------------=

Basic error

7.5 

0.00385  /  C100 

--------------------------------------------------------------------------------- -

19.5 C==

Error due to amb. temp. var. of 25 °C

0.0039  /  C25 C 7.5 

0.00385  /  C100

-------------------------------------------------------------------------------------------------------

1.9 C==

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Emerson 644 User manual

Brand: Emerson

Model: 644

Category: Measuring, testing & control

Type: User manual

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Emerson 644 User manual

Emerson 644 User manual

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